after thinking about the possibilities for this server "transient failure"
I would recommend rescue in the local Filesystem on server status (#4.3.0) independent of config for folder 'sent' and folder 'draft'
make a subdirectory "rescue" in the local File System below local ARCHIVE folder and put the email in here.
this is independent of the server BUSY problem.
the file in 'rescue' folder can now easily retried later and is not 'lost on transit'
after thinking about the possibilities for this server "transient failure"
I would recommend rescue in the local Filesystem on server status (#4.3.0) independent of config for folder 'sent' and folder 'draft'
make a subdirectory "rescue" in the local File System below local ARCHIVE folder and put the email in here.
this is independent of the server BUSY problem.
the file in 'rescue' folder can now easily retried later and is not 'lost on transit'